Patch-mainline: v6.1-rc5
Git-commit: f6d58266d731fd7e63163790aad21e0dbb1d5264
References: git-fixes
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Mon, 7 Nov 2022 04:17:29 -0500
Subject: [PATCH] KVM: SVM: retrieve VMCB from assembly
Continue moving accesses to struct vcpu_svm to vmenter.S. Reducing the
number of arguments limits the chance of mistakes due to different
registers used for argument passing in 32- and 64-bit ABIs; pushing the
VMCB argument and almost immediately popping it into a different
register looks pretty weird.
32-bit ABI is not a concern for __svm_sev_es_vcpu_run() which is 64-bit
only; however, it will soon need @svm to save/restore SPEC_CTRL so stay
consistent with __svm_vcpu_run() and let them share the same prototype.
No functional change intended.
Cc: stable@vger.kernel.org
Fixes: a149180fbcf3 ("x86: Add magic AMD return-thunk")
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
---
arch/x86/kvm/kvm-asm-offsets.c | 2 ++
arch/x86/kvm/svm/svm.c | 5 ++---
arch/x86/kvm/svm/svm.h | 4 ++--
arch/x86/kvm/svm/vmenter.S | 20 ++++++++++----------
4 files changed, 16 insertions(+), 15 deletions(-)
diff --git a/arch/x86/kvm/kvm-asm-offsets.c b/arch/x86/kvm/kvm-asm-offsets.c
index 30db96852e2d..f1b694e431ae 100644
--- a/arch/x86/kvm/kvm-asm-offsets.c
+++ b/arch/x86/kvm/kvm-asm-offsets.c
@@ -15,6 +15,8 @@ static void __used common(void)
if (IS_ENABLED(CONFIG_KVM_AMD)) {
BLANK();
OFFSET(SVM_vcpu_arch_regs, vcpu_svm, vcpu.arch.regs);
+ OFFSET(SVM_current_vmcb, vcpu_svm, current_vmcb);
+ OFFSET(KVM_VMCB_pa, kvm_vmcb_info, pa);
}
if (IS_ENABLED(CONFIG_KVM_INTEL)) {
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b412bc5773c5..0c86c435c51f 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3914,12 +3914,11 @@ static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
- unsigned long vmcb_pa = svm->current_vmcb->pa;
kvm_guest_enter_irqoff();
if (sev_es_guest(vcpu->kvm)) {
- __svm_sev_es_vcpu_run(vmcb_pa);
+ __svm_sev_es_vcpu_run(svm);
} else {
struct svm_cpu_data *sd = per_cpu(svm_data, vcpu->cpu);
@@ -3930,7 +3929,7 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
* vmcb02 when switching vmcbs for nested virtualization.
*/
vmload(svm->vmcb01.pa);
- __svm_vcpu_run(vmcb_pa, svm);
+ __svm_vcpu_run(svm);
vmsave(svm->vmcb01.pa);
vmload(__sme_page_pa(sd->save_area));
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 447e25c9101a..7ff1879e73c5 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -683,7 +683,7 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm);
/* vmenter.S */
-void __svm_sev_es_vcpu_run(unsigned long vmcb_pa);
-void __svm_vcpu_run(unsigned long vmcb_pa, struct vcpu_svm *svm);
+void __svm_sev_es_vcpu_run(struct vcpu_svm *svm);
+void __svm_vcpu_run(struct vcpu_svm *svm);
#endif
diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 531510ab6072..d07bac1952c5 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -32,7 +32,6 @@
/**
* __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode
- * @vmcb_pa: unsigned long
* @svm: struct vcpu_svm *
*/
SYM_FUNC_START(__svm_vcpu_run)
@@ -49,16 +48,16 @@ SYM_FUNC_START(__svm_vcpu_run)
push %_ASM_BX
/* Save @svm. */
- push %_ASM_ARG2
-
- /* Save @vmcb. */
push %_ASM_ARG1
+.ifnc _ASM_ARG1, _ASM_DI
/* Move @svm to RDI. */
- mov %_ASM_ARG2, %_ASM_DI
+ mov %_ASM_ARG1, %_ASM_DI
+.endif
- /* "POP" @vmcb to RAX. */
- pop %_ASM_AX
+ /* Get svm->current_vmcb->pa into RAX. */
+ mov SVM_current_vmcb(%_ASM_DI), %_ASM_AX
+ mov KVM_VMCB_pa(%_ASM_AX), %_ASM_AX
/* Load guest registers. */
mov VCPU_RCX(%_ASM_DI), %_ASM_CX
@@ -170,7 +169,7 @@ SYM_FUNC_END(__svm_vcpu_run)
/**
* __svm_sev_es_vcpu_run - Run a SEV-ES vCPU via a transition to SVM guest mode
- * @vmcb_pa: unsigned long
+ * @svm: struct vcpu_svm *
*/
SYM_FUNC_START(__svm_sev_es_vcpu_run)
push %_ASM_BP
@@ -185,8 +184,9 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run)
#endif
push %_ASM_BX
- /* Move @vmcb to RAX. */
- mov %_ASM_ARG1, %_ASM_AX
+ /* Get svm->current_vmcb->pa into RAX. */
+ mov SVM_current_vmcb(%_ASM_ARG1), %_ASM_AX
+ mov KVM_VMCB_pa(%_ASM_AX), %_ASM_AX
/* Enter guest mode */
sti
--
2.35.3